Automatic dry pipe sprinkler system



Nov. 19, 1935. w. K. HDGMAN, JR

f AUTOMATIC DRY PIPESPRINKLER SYSTEM 3 Sheets-Sheet 2 Filed Sept. 16, 1932 Yigg.

' Nov. 19, 1935. w. K. HODGMAN, JR i 2,021,148

AUTOMATIC DRY PIPE SPRINKLER SYSTEM Filed sept. 1e, 1952 K 5 sheetysneet s Fig.

\ |nvenToT. l Willis K. Hodgman dr. A'ys.

Patented Nov. 19, 193.5

UNITED STATES ATENT OFFICE AUTOMATIC DRY PIPE SPRINKLER SYSTEM 9 Claims.

This invention relates to that type of automatic dry pipe sprinkler systems in which provision is made for admitting Water into the sprinkler piping previous to the operation of. any of the automatic sprinklers thus to enable prompt discharge of the water when the sprinkler opens. ln such a system the control valve or dry pipe valve, which when open admits the water to the sprinkler piping, is caused to open by the action of any one of a series of suitable heatdetecting units located at various points in the areas protected by the sprinklers. These heatdetecting units may be of various types but operate upon a predetermined rise in temperature. Such a predetermined rise in temperature may be either the attainment of a predetermined ternperature lower than the temperature at which the sprinkler heads are set to open or a predetermined rapid rate of rise in temperature such, for example, as would be induced by the heat caused by nre.

The chief object of the present invention is to provide such a system in which an electric circuit under the control of the heat-detecting units acts to effect the opening of the dry pipe` valve and the consequent admission of water to the sprinkler system before the opening of a sprinkler head and in which the electric circuit is under constant supervision thus to insure prompt detection of any failure of the circuit which would cause failure of the dry pipe valve to open upon operation of a heat detecting unit and in which the dry pipe valve is always free to function in the usual Way upon the opening of a sprinkler head even if the mechanism provided fails to effect the opening of the dry pipe valve before the opening of the sprinkler head and in which neither the failure of the electric circuit nor the operation of the supervisory mechanism acts to effect the opening of the dry pipe valve.

A further object of the invention is to provide a simple and effective system which may be readily attached to or embodied in automatic dry pipe valve sprinkler systems already installed and which shall be of a rugged and reliable nature having a minimum of parts that are liable to fail cr get out of order and guarded against accident cr against tampering Without prompt detection thereof.

A further object of the invention is to provide a system in which the water when admitted to the sprinkler piping in advance of the opening of a sprinkler head will pass by the most direct course to the sprinkler head when it opens.

These and other objects and features of the invention will appear more fully from the accompanying description and drawings and will be particularly pointed out in the claims.

In the drawings:

Fig. l is a more or less diagrammatic View of a portion of an automatic dry pipe valve sprinkler system embodying a preferred form of the present invention.

Fig. 2 is a detail chiefly in vertical cross section showing one form of dry pipe valve and the immediate connections for by-passing and controlling the by-passing of the air from the sprinkler side of the system to the intermediate chamber between the air and Water clappers.

Fig. 3 is a detail partially broken away and 15 partially in cross section illustrating a form of the invention in which the air is vented from the sprinkler side of the system to effect the opening of the dry pipe valve.

The dry pipe valve I which may be of any suitable construction but is here shown by way of example as of the construction illustrated in the patent to Hodgman, No. 1,856,333, May 3, 1932, is mounted on the top of the water supply pipe 2 and from it extends upwardly the main riser 3 25 of the sprinkler piping. From this riser 3 extend as usual branch pipes such as 4 from which in turn extend sub-branch pipes 5. Sprinkler heads 6 are located at suitable intervals in the branch piping as required by the conditions. While the branches 5 are shown for convenience of illustration extending parallel to the riser 3, it will, of course, be understood that the branch piping is so arranged that the sprinkler heads are directed toward the areas to be protected by water and consequently usually point upward. These sprinkler heads 5 may be of any suitable type and, as is well known, are arranged to open when a predetermined temperature has been reached.

The dry pipe valve as disclosed in the aforesaid patent comprises a Water clapper 'l cooperating with a seat 3 and an air clapper 9 cooperating with a seat I3. 'Ihe intermediate chamber II between these two clappers is normally open to the atmosphere and the construction is such that a relatively low pressure of air above the air clapper 9 maintains ther clappers closed against a relatively high water pressure below the water clapper l, all as well understood in this art.

In the form of the invention illustrated in Figsf 1 and 2, a by-pass pipe I2 connects the system above the air clapper 9 to the intermediate chamber I l and for that purpose is shown as threaded at I3 into the wall of the dry pipe valve at the intermediate chamber and connected at I4 into 55 the lower end of the riser 3. A valve casing I5 containing a Valve I6 is inserted in the by-pass I2 and this Valve is normally closed. When this valve is open, however, air will at once pass from the riser 3 into the intermediate chamber I I and this air being under pressure will at once close the small check valve I1 described in the aforesaid patent and at once the pressure in the intermediate chamber II will become equal to the pressure in the sprinkler system above `the air clapper 9, thus neutralizing the diierential which previously existed between the air and water` pressures and allowing the higher pressure of ,the waterV to throw the water and air clappers to open position and admit the water to the sprinkler system.VV

In the preferred construction the Valve such as I3 in the by-pass is opened by the action of any one of a series of the heat-detecting units. These heat-detecting units, as previously pointed out, are located at desired points adjacent the sprinkler heads throughout the areas to be protected.

The heat-detecting units I8 are of that type which operate when a predetermined temperature less than that at which the sprinkler heads operate has been attained and the operation upon the attainment of this temperature is such as toreifect the closing of an electric circuit. The heat-detecting units I9 are of that type which operate when a predetermined rapid rate of rise in temperature takes place, such, for example, as caused by the heat generated by iire and the operation is such as to be effective in closing an electric circuit. As both types of such heatdetectingV units areV well known, it is only necessary to illustrate them diagrammatically.

' In the construction illustrated, the arrangement is such that both types of heat-detecting units are installed and the Valve I6 will be operated upon the operation of either but it is obvious that only one type may be employed or that the different types may be employed in different places as found desirable.

An electric circuit is employed for eiecting the opening of the valve I5 upon the operation of a heat-detecting unit.

In the construction illustrated, the valve casing i5 is extended at 2U to form a chamber 2I closed at one end by a exible diaphragm 22.

diaphragm. The space 24 at the valve side of the diaphragm 22 opens into the Valve casing I5 and consequently through the by-pass and the intermediate chamber I I is normally open to the atmosphere. A small by-pass 25 extends through the casing wall from the chamber 2I and opens into the space 26 so that the air pressure of the sprinkler system is normally maintained in the chamber 2l. Y Consequently the valve IB is held by the air pressure in the Chamber 2| normally against itsY seat and the by-pass I2 is closed. A Valve 21 opening from the chamber 2l to the atmosphere is also normally held closed by the pressure in the chamber 2I. This valve 21 iscarried by the core 28 of a solenoid 29. If now the solenoid be energized, the core 28 will beprojercted upward opening the valve 21, releasing the pressure inthe chamber 2|, and at once the valve lli will be forced open by the air pressure in the system and this air pressure will be produced inthe intermediate chamber l i, causing the clappers of the dry pipe valve to open `in the manner already described.

VThe electric circuit in which the invention is embodied extends at 3G from the solenoid 29 through a suitable source of electric energy such A as a battery 3i through an alarm bell 32, thence through a small power solenoid 33, thence at 34 to a resista-nce 35, thence at 35 back to the solc- 5 noid 25. The solenoid 33 controls a switch 31 in an auxiliary circuit 38 having therein a battery 35 and a supervisory alarm bell 43. The resistance 35 is such that only a small current ows in the circuit thus described insuiiicient to ener- 10 gize the solenoid 29, but suicient to energize the solenoid 33 and maintain the circuit 33 open.

If the main circuit is broken or tampered with, the small currentl thus ilowing is broken, the solenoid 33 is deenergized and the switch 31 15 closes, causing current from the battery 33to flow inthe circuit 38 and the supervisory alarm bell 40 to sound. VIt will thus be seen that the `main circuit is under constant supervision and in case of any failure for any reason, that fact 20 is at once evidenced by the sounding of the supervisory alarm bell 43.

The detecting units are positioned wherever desired in the main circuit butV in each case 'so as to shunt the resistance 35 when either acts 25 to close the main circuit. Thus when any heatdetecting unit acts, the resistance 35 is thrown out of the circuit and the full power of the battery 3! or other source of electric energy passes through the circuit energizing the solenoid 29 and 30 effecting, in the manner described, the opening of the dry pipe valve. f The alarm bell 32- is of a type which requires more power to sound than is exerted by the small supervisory current normally flowing through the 35 main circuit 'and the resistance 35 but which is sounded when the resistance 35 is cut off. Conl sequently whenever a heat-detecting unit acts, the alarm bell 32 sounds. This is of great advantage because it enables the nre to be located 40 and frequently extinguished before a temperature'has been reached sufficient `to open the sprinkler head, and thus prevents water damage. While in the preferred form of the invention the opening of the dry pipe valve is eiected in 4 Y the manner already described by byV-passing the air pressure from the sprinkler system to` the intermediate chamber, many advantages of the invention, as already pointed out, may be obtained in that type of apparatus in which the 50 opening of the dry pipe valveV previous to theV operation of a sprinkler head is effected by venting air from the sprinkler system. An apparatus of this type actuated from the same electric system as shown in Fig. 1 is illustrated'in Fig. 55 3. In this construction a tting 4I is inserted between the riser 42 of the sprinkler system and the dry pipe 'valve 43. A plug 44 is threaded into the side of the ttingAI. This Vplug has a central bore into which is threaded the end of the 60 vent ,pipe 45. YA small check valve 45 is pivoted at 41 on the plug 44 and normally extends out as shown in full lines into the path of the water when it howsV into the system. The vent pipe 45 extends into a Valve casing 48. This 65 valve casing maybe of the same construction and contain the same arrangement of valve, diaphragm, and chambers as shown in Fig. 2 and described in connection therewith and the valve therein may be controlled by a solenoid :i9 in the 7 0V manner already described. The lower end of the casing 48 below the valve in the casing opens to the atmosphere through the pipe 55. Y

It will thus be seen that under normal con-V ditions the vent pipe 45 is closed and the solenoid 75 CFI 4S is deenergized except by the very small super'- visory electric current. When a` heat-detecting unit operates, thissolenoid 69. is energized and the vent pipe 45. is opened by the valve in the casing d8. This causes the air to rush out through the pipe d5 from the sprinkler system until the pres` sure above the dry pipe valve is reduced sufciently to neutralize the differential in the air and water pressures acting on the air and water clappers, whereupon the clappers open andthe water rushes into the sprinkler system. This inrush of water at once throws the small check valve 4S into closed or dotted line position, thus preventing any escape of water through the ventY pipe d5, and as the pressure in the sprinkler system is always greater than that of the atmosphere, this check valve 46 when once closed remains closed.

There is thus presented by this invention a simple and efficient mechanism for securing the admission of water to the system of sprinkler piping before the sprinkler heads operate so that when they do operate, the water is immediately discharged from the sprinkler to extinguish the re. This mechanism is read-- ily adapted to existing dry pipe systems and in no Way interferes with the usual or normal operation of the dry pipe valve when a sprinkler head operates. Furthermore, the mechanism is under constant supervision so that if for any reason it fails to operate, an alarm is instantly given. The mechanism also acts when operated in advance of the operation of the sprinkler head' to sound a main alarm and thus frequently to enable the fire to be reached and extinguished before the sprinkler heads operate to discharge water. In the preferred form of the invention where the opening of the air and water clappers is effected by by-passing the air from the sprinkler side of the system to the chamber intermediate the clappers, the water admitted to the sprinkler system moves directly to the rst sprinkler head that opens without filling up much of the piping that is not required to carry the Water to the sprinkler head because the other branches of the piping still retain air under a substantial amount of pressure which tends to prevent the water from entering therein. This is a further advantage in the subsequent draining of the system and especially in very cold weather because the less the amount o-f water which has to be drained from the system, the less likelihood there is of damaging by freezing.

While in the particular form of apparatus illustrate-d the current in the electric circuit is increased to effect the operation of the auxiliary means, it is obvious that an increase of currentin this circuit is but an example of one form of alteration of the current so far as the broader aspect of the invention is concerned. The essential characteristics of the invention are that there shall be an auxiliary means which is operable to eifect the opening of the clapper means and allow the water to enter the system, that this auxiliary means shall be operated by an electric circuit, that this electric circuit shall act only when closed thus to effect operation of the auxiliary means, that this circuit shall be normally closed, that this circuit when thus closed shall have normally therein a current incapable of effecting the operation of the auxiliary means, and that the detecting means shall operate to alter the current in the electric circuit and through this alteration effect the operation of the auxiliary means, and nally that supervisory means shall act to indicate failure of the electric` circuit or of the. current therein. Thus the auxiliaryv means for opening the clapper means is controlled byv an electric circuit which may be readily installed,

this circuit is under constant supervision by the 5.

supervisory means, any'failure of the circuit while indicated by the supervisory means does not act to effect the operation of the auxiliary means but. whenever the detecting means does act, the auxiliarymeans` is operated to effect in turn the opera-y 10, tion. of. the clapper means and the entry of the water into the system.

Having thus described the invention, what is claimed as new, and desired to be secured by Letters Patent, is: 15.

l'. An automatic dry pipe sprinkler system comprising a piping system, temperature controlled sprinkler heads therein, a dry pipe valve having clapper means normally held closed against the` water pressure by the air pressure 20,

in the system, auxiliary means operable to effect the opening of the clapper means and allow the water to enter the system, an electric circuit acting only when closed tov operate the auxiliary means, the said circuit being normally closed but 25 having normally therein a current incapable of effecting such operation whereby failure of said circuit or of the current therein will not act to effect the opening of the clapper means, temperature detecting means operating, upon a predeter- 30 mined rise in temperature at a fixed location insuiiicient to open an adjacent sprinkler head, to alter the strength of the current in the electric circuit and through said alteration to effect the operation of the auxiliary means, and supervisory 35 means acting to indicate failure of the electric circuit or of the current therein.

2. An automatic dry pipe sprinkler system comprising a piping system, temperature controlled sprinkler heads therein, a dry pipe valve 40 having clapper means normally held closed against the water pressure by the air pressure in the system, auxiliary means operable to effect the opening of the clapper means and allowr the Water to enter the system, an electric circuit acting only when closed to operate the auxiliary means, the said circuit being normally closed but having normally therein a current insufficient to effect such operation whereby failure of said circuit or of the current therein will not act to rent therein. v

3. An. automatic dry pipe sprinkler system comprising a piping system, temperature controlled sprinkler heads therein, a dry pipe valve having clapper means normally held ciosed against the water pressure by the air pressure in the system, auxiliary means operable. to effect the opening of the clapper means and allow the water to enter the system, an electric circuit acting only when closed to operate the auxiliary means, the said circuit being. normally closed but having normally therein a current insufficient to effect such loperation whereby failure of said circuit or of the current therein will not act to effect the opening of the clapper means, temperature detecting means operating, upon the attainment of a predetermined temperature at a fixed location insufficient to open an adjacent sprinkler head, to increase the current in the electric circuit to that requisite to operate the auxiliary means Vand through said increase to effect such operation, and supervisory means acting to indicate failure of the electric circuit or of the current therein.

4. An automatic dry pipe sprinkler system comprising a piping system, temperature controlled sprinkler heads therein, a dry pipe valve having clapper means normally held closed against the water pressure by the air pressure in the system, auxiliary means operable to effect the opening of the clapper means and` allow the Water to enter the system, an electric circuit acting only when closed to operate the auxiliary means, the said circuit being normally closed but having normally therein aY current insufficient to effect such operation whereby failure of said circuit or of the current therein will not act to effect the opening of the clapper means, temperature detecting means operating, upon a predetermined rapid rate of rise in temperature at a fixedV location insufficient to open an adjacent sprinkler head, to increase the currentl in the electric circuit to that requisite to operate the auxiliary means and through said increase to effect such operation, and supervisory means acting to indicate failure of the electric circuit or of the current therein.

5. An Vautomatic dry pipe sprinkler system comprising a piping system, temperature controlled sprinkler heads therein, a dry pipe valve having clapper means normally held closed.

against the water pressure by the air pressure in the system, auxiliary means operable to effect the opening of the clapper means and allow the water to enter the system, an electric circuit acting only when closed to operate the auxiliary means, the said circuit being normally closed but having normally therein a current incapable of effecting such operation whereby failure of said circuit or of the current therein will not act to effect the opening of the clapper means, temperature detecting means operating, upon a predetermined rise in temperature at a xed loca- 'Vtion insufficient to open an adjacent sprinkler head, to alter the current in the electric circuit and through said alteration to effectV the operation of the auxiliary means, an alarm actuated by the electric circuit upon the operation of the temperature detecting means and supervisory means acting to indicate failure of the electric circuit or of the current therein,

6. An automatic dry pipe sprinkler system comprising a piping system, temperatureY controlled sprinkler heads therein, a dry pipe valve having clapper means normally held closed against the water pressure by the air pressure in the system, auxiliary Ymeans operable to effect the opening of the clapper means and allow the water to enterithe system, an electric circuit Vacting only when closed to operate the auxiliary means, the said circuit being normally closed but having normally therein a current incapable of effecting such operation whereby failure of said circuit or of the current therein will not act to effect the opening of the clapper means, temperature detecting means operating, upon a predetermined rise in temperature at a fixed location insunicient to open an adjacent sprinkler head, to alter the current in the electric circuit, and through said alteration tojeifect the operation of the auxiliary means, an alarm actuated by the electric circuit upon the operation of the temperature detecting means, a supervisory alarm, and supervisory means acting to actuate the supervisory alarm and to indicate failure of the electric circuit or of the current therein.

7. An automatic dry pipe sprinkler system comprising a piping system, sprinkler, heads therein, a dry pipe valve having clapper means normally held'closed against the Water pressure, auxiliary means operable to effect the opening of the clapper means and allow the Water to enter the system, an electric circuit acting only when closed to operate the auxiliary means, the said circuit being normallyclosed but having normally therein a current incapable of effecting such operation whereby failure of said circuit or of the current therein will not act to effect the opening of the clapper means, temperature detecting means operating, upon a predetermined rise in temperature at a xed location, to alter the current in the electric circuit and through said alteration to effect the operation of the auxiliary means, and supervisory means acting to indicate failure of the electric circuit orof the current therein. i

8. An automatic dry pipe sprinkler system comprising a piping system, a'dry pipe valve having clapper means normally held closed against the water pressure, auxiliary means operable to effect the opening of the clapper means and to allow the water to enter the system, an electric circuit acting only when closed to operate the auxiliary means, the said circuit being normally closed but having normally therein a current insufficient to effect, such operation whereby failure of said circuit or of the current therein will not act to effect the opening of theV Y Y clapper means, temperature detecting means operating, upon a predetermined rise in temperature at a fixed location, to increase the current j in the electric circuit to that requisite to operate the auxiliary means and through said increase to eifect such operation, and supervisory means acting to indicate failure of the electric circuit or of the current therein.

9. An automatic dry pipe sprinkler system comprising a piping system, sprinkler heads therein, a dry pipe valve having clapper means normally held closed against the water pressure, Y

opening of the clapper means, temperature detecting means operating, upon a predetermined rise in temperature at a xed location, to alter the current in the electric circuit and through said alteration to effect the operation .of the auxiliarymeans, an alarm actuated by the electric circuit upon the operation of the temperature detecting means, a supervisory alarm and supervisory means acting to actuate the supervisory alarm and to indicate failure of the elec- -tric circuit or of the current therein.

WILLIS K. HODGMAN, JR. 

